Porcine Reproductive and Respiratory Syndrome Virus: Epidemiology

Abstract

This is a brief overview of the current situation regarding PRRSV, with an emphasis on information that has appeared in the literature within the last 5 years. This period has been marked by 1) A growing recognition of the high cost of PRRS to swine producers; 2) Continued producer frustration with the (poor) control of PRRS; 3) Heightened interest in regional elimination of PRRSV, but reluctance to proceed without more reliable methods of achieving the objective; 4) Reports (and "counter reports") of newly emerging, highly virulent, PRRSV isolates; and 5) Innovation in the application of diagnostics to surveillance. PRRSV CHANGES IN GLOBAL DISTRIBUTIONPRRSV was diagnosed in Africa for the first time in June 2004 following outbreaks in Western Cape Province, South Africa (OIE, 2005a). Steps were taken to eliminate the disease, i.e., quarantine, stamping out, premise disinfection. Serologic tests did not identify additional infected sites at that time, but new outbreaks were identified in October 2005 (OIE, 2005b) and again in August 2007 (Beltran-Alcrudo et al., 2007). A source of the virus has not been determined and remains a point of strong interest.Chile is on the verge of becoming the first country to eradicate PRRSV. Begun in 2001, by Chilean swine producers organization (ASPROCER) in coordination with animal health government agencies, the national PRRSV eradication program is close to achieving its objective. According to the Chilean swine producers organization (ASPROCER), the last PRRSV-positive pigs were sent to the abattoir on April 2, 2007. Chilean producers are currently in the process of culling all sows that were present at the time of infection (Anon, 2007). ECONOMICSThe cost of PRRS due to reproductive outbreaks was recognized early in the PRRSV pandemic, e.g., in 1990Polson et al. (1990 estimated losses at $236 USD per sow during an acute outbreak of reproductive PRRS due to infertility, abortions, stillbirths, and neonatal mortality. More recently, there is a developing recognition of the cost of PRRSV infection in

Development and Validation of an Objective Risk Scoring System for Assessing the Likelihood of Virus Introduction in Porcine Reproductive and Respiratory Syndrome Virus-Free Sow Farms in the US

“…Questions in all of the internal and external risk sections were included in the GLLR risk scoring system suggesting that all of the routes of transmission that were considered in this study were important enough to be included in the risk scoring system. This is consistent with the body of research demonstrating the importance of multiple routes by which PRRS virus is transmitted [17].…”

Effect of temperature and relative humidity on the stability of infectious porcine reproductive and respiratory syndrome virus in aerosols

“…Following its introduction into the domestic swine population, probably some time in the 1970's, the virus spread rapidly and at present, the herd-level prevalence of infection generally exceeds 60% in swine-dense regions of the world [46].…”

The Splay Leg Syndrome in Piglets: A Review

“…Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) cause late term reproductive failure in sows, which is characterized by increased number of stillbirth, weak, light weight and splay-legged piglets (Papatsiros et al, 2006;Zimmerman et al, 2006). Clinical signs: Affected piglets are characterized by an obvious weakness of the hind limbs immediately after birth leading to impaired mobility (Bergmann, 1976).…”